From practice, a so-termed drivable torsion beam axle or electric twist beam (ETB) is known, in which an electric passenger car drive is integrated in a rear torsion beam axle. In this case an ETB has, respectively on the left and right wheel, a compact unit or drive-train which comprises a transmission and an electric motor. In each case, the drive-train is arranged in a housing which is in turn part of a trailing arm. The two trailing arms, respectively arranged on the outsides of the vehicle, are connected to one another by means of a transverse profiled element extending essentially in a transverse direction of the vehicle and can be connected to the vehicle body in the area of main mountings. Furthermore, when installed in the vehicle the trailing arms are additionally coupled to a vehicle body by spring and damper units. By virtue of the two separate drive-trains, among other things a selective, wheel-individual torque distribution, the so-termed torque vectoring, can be implemented.
Furthermore, DE 10 2011 005 625 A1 describes a drive device for driving a wheel of a torsion beam axle of an electrically powered vehicle, which comprises an electric machine and a transmission connected on the drive output side of the electric machine as viewed in the force flow direction during traction operation. The housing of the electric machine or the housing of the transmission are bolted directly to the trailing arm of the torsion beam axle, or integrated as a multi-component welded structure in the trailing arm, or made integrally as one piece with the trailing arm. Moreover, the electric machine and the transmission can have a common housing.
Housings of the electric machine and/or the transmission made integrally with the trailing arm conflict with the desire to produce the transmission and/or the electric machine of an ETB as a module that can be preassembled, which during final assembly can be connected to the trailing arm simply and inexpensively.
In contrast, housings of the transmission and/or the electric machine connected to the trailing arm by bolt connections, by way of which tire forces have to be passed on toward the vehicle body, are undesired. This results from the fact that during driving operation of a vehicle made with an ETB, bolt connections between a housing of a transmission and/or an electric machine and a trailing arm are exposed to alternating stresses which affect a sealing device in the area of the parting joint between the housing and the trailing arm to an undesired extent. To ensure a durable sealing effect, more sealing effort and expense has to be spent on that area, but this makes the production of an ETB more costly overall.